First this webmaster want to debunk the fallacies in regards to the equation of the ancient Yu-shi tribe to the Yuezhi, and the speculation on the jade trade that the Yuezhi was falsely accredited with.

The forged Guan-zi [管子] statement contained a reference which was a misnomer related to the 'Yu-shi' tribe, a term that was erroneously speculated by a few annotators in history, as well as scholar Wang Guowei of the early 20th century,
to be the same as Yuezhi per soundex.
What Guan Zhong (Guan Zi) was alleged to have said was a statement using an ancient Chinese syntax to juxtapose two equally valuable things, i.e., the jade from the Yu-shi tribe to the north versus the pearls from the Yangtze to the south.
This webmaster likes to point out that the Yu-shi tribe [and the Bai-di barbarian --who enjoyed the same last name 'Ji1' as the Zhou Dynasty royal court, by the way] that Qi Lord Huan'gong had campaigned against in the 7th century B.C. was right next to the East Yellow River Bend, not the Yuezhi that was recorded in the 3rd century B.C. as dwelling between the Qilian mountain and the later Dunhuang grottos.
See this webmaster's discussion at tarim-mummies-and-the-introduction-of-chariots/page__st__15

Here, mark this webmaster's words: Yu-shi, having absolutely nothing to do with the Yue-zhi people [as erudite Wang Guowei claimed --a No. 1 blunder of the most famous Chinese scholar of the 20th century], could be taken as either the western Yu [Wu] or the northern Yu [Wu] remnants from the descendant of one of the two elder brothers who 'emigrated' to the Yangtze River and the Taihu Lake 3000 years ago.

Qi Lord Huan'gong's 7th cent. B.C. campaign against the Bai-di and Yu-shi, a military action that the hegemony lord conducted to win the respect among the Zhou vassals on the ground of defending the Zhou Dynasty court, was an obscure record in the Chinese history. Around the Xin (New) Dynasty (AD 6-23) time period, there occurred
forgeries by the Chinese scholars, possibly with the intention of substantiating the mandate of the usurper Wang Mang's dynasty.
The classics which were proved to be forgeries
include "Guan-zi [管子]", which historian Ma Feibai pierced sentence by sentence.
(The book "Guan-zi [管子]" was very much a polemic political economy book which centered around the statesmen’s leverage of the economic policies in ruling a country, in which
extensive citation was made, albeit using the Han Dynasty and Xin Dynasty's terminologies and events unwittingly, such as the theme of the salt-iron debates of the western Han Dynasty.
See Preliminary Discussions on the Forgeries in the Chinese Classics
for this webmaster's rebuttals on the additional forged books of Guan-zi.)

Using Ma Feibai's same logic, this webmaster had found two other books, "Yi-zhou-shu" [逸周书] or "Zhou-shu" (Zhou Dynasty [1050 B.C. - 256 B.C. per THE BAMBOO ANNALS] [abbrev. 周书] book,
not the Zhou-shu [周书] from the Posterior Zhou Dynasty of the South-North Dynasty time period of AD 557-581) and "Shang[1]-shu" [商书] (Shang Dynasty [the 16-11th cent. B.C.; or 1559 - 1050 B.C.E. per THE BAMBOO ANNALS] book, not Shang[4]-shu [尚书], i.e., the remotely ancient book which was said to be abridged by Zuo Qiuming [Zuoqiu Ming]),
to be written in the exact same style and could be forgeries by possibly the same person[s].
In the apparently forged Yi-zhou-shu [逸周书] and Shang-shu [商书] books, you could find sentences redundantly listing the names
of the barbarian tribes and vassals as known in Han Emperor Wudi's reign of B.C. 140-86, including the name of Yuezhi to be some alien tribe to have surrendered
tributes as early as during the Shang Dynasty, which was quite an irony, not to mention the forgery in conveniently penning a boundary of the Chinese Shang Dynasty
central kingdom as well as positions of the various alien tribes and vassals per then-known knowledge as of the 1st century A.D.

Discarding the forgery of Guan-zi [管子] basically eliminated the whole foundation upon which the existence of the Yuezhi jade trade was built,
a fallacy which was widely cited by people inside and outside of China in
the most recent 10-20 years, i.e., the 1990s and 2000s, to the effect that the fabricated Yuezhi had lived close to the heart of China, playing the role of bearing the Aryan civilization (i.e., the iron technology, chariots etc) to China.

Though, if you read history word for word for what it was, then in the 10th century B.C.E., Zhou King Muwang had indeed resettled the barbarians at the origin of the Jingshui and Weishui Rivers, including the later five Rong groups named as Yiqu, Yuzhi, Wuzhi, Xuyan and Penglu.
The naming here contained some soundex more closely mapping the Yuezhi people than any other terms as recorded in the Chinese history, and more, the location was very much a match as well. (Among the five Rongs, the Yiqu had grown to be the most dominant group and controlled the majority of the central and northern Shenxi province as known today, till the 4th century and 3rd century B.C.E., when it was absorbed by the Qin empire.)

Twenty years of testing on the jade articles from the Xia, Shang and Zhou tombs, from which there were unearthed a large number of jade artifacts for ritual and oblation,
failed to link the artifacts to the Khotan jades. The test also eliminated the source of jades as from other major jade sites such as the Liaoning Xiuyan Jade mine in Manchuria, nor the inner land jade such as the Nanyang Dushan Jade mine in Henan Province.
Mt Kunlun, in ancient China, meant for Mt Qilianshan, with Kunlun meaning magnificent and heavenly, which the later Huns called by a similar name in their terminology, i.e., Qilian, a word meaning 'Heaven'.
In the late Western Jinn Dynasty, during the 5th century A.D., Zhang Gui, a Chinese magistrate at the Western Corridor (Ganzhou [Zhangye of Gansu], Liangzhou [Wuwei of Gansu], Guazhou [east of Gansu-xian/Anxi-xian of Gansu], Shazhou [Dunhuang of Gansu]), established,
at the northern foot of Qilian Mountain, the Former Liang State (301-76). Serving under him will be a Jiuquan magistrate who pointed out that the Qilian Mountain southwest of Jiuquan would be where Zhou King Muwang met the Queen Mother of the West.
At http://www.imperialchina.org/Zhou_Dynasty.html this webmaster previously stated
that "Zhou King Muwang (r. 1001-946 BC [962-908 per BAMBOO]) was a legendary figure famous for fighting in the west -- and per Charles Hucker maybe today's Central Asia --
where he met and had rendezvous on Kunlun Mountain with so-called 'Xi Wang Mu', namely, the Queen Mother of the West, who was rumored by the Western historians,
including Charles Hucker, to be the Queen of Sheba. (The actual place for the Kunlun Mountains would be
somewhere close to today's Jiuquan County, Gansu Province. Or, also likely, it could be today's Mt Helanshan on the west bank of the West Yellow River Bend.)"
At http://www.imperialchina.org/Huns.html this webmaster stated that
Zhou King Muwang was noted for defeating the barbarians, reaching today's Qinhai-Gansu regions in the west, meeting with the Queen Mother of West on Mt Kunlun [possibly around the Dunhuang area], and then relocating the barbarians eastward to the starting point of the Jing-shui River for better management [in a similar fashion to Han Emperor Wudi's relocating the Southern Huns to the south of the north Yellow River Bend]."
(At the upperstream Weishui and Jingshui rivers, there was a yellow mud plateau named the Queen Mother Palace where Xu Haidong's Red Army fought a battle.
As to Zhou King Muwang's travelogue, it could be a 4th century B.C.E. fiction that was built on the limited early Zhou Dynasty records as well as the then-available knowledge about the northwestern frontier as of maybe the 4th century B.C.E.
In another word, Zhou King Muwang, whose reign was about half a century, did not actually travel across the whole domain of China as the travelogue stated. Zhou King Muwang did campaign against the barbarians in the 10th century B.C.E. and rounded up some of the barbarians for resettlement at the origin of the Jing-shui/Wei-shui Rivers, which caused the other part of the [unconquered] barbarians to stop sending the tributes or paying visits to the Zhou court. The [conquered] barbarians, who resettled at the Jingshui and Wei-shui rivers, could later have moved east to first be part of the Li-rong barbarians who sacked the Western Zhou capital Haojing and then crossed the East Yellow River Bend to be the so-called Bai-di and Chi-di barbarians, namely, the so-called Quan-rong barbarians that Zhou King Muwang purportedly met in today's northwestern Shanxi Province in the travelogue which was written in the 4th century B.C.E.)

This webmaster likes to quickly debunk one more myth before continuing on to the topic of human migration.
The cronies who had been propagating the Aryan bearers of the Chinese civilization, like by J. P. Mallory and Victor H. Mair and et al., had one more
weird claim in regards to what the "giants" meant in SHI JI, other than the Yuezhi jade trade fallacy.
Sima Qian recorded an episode about Qin Emperor Shihuangdi's collecting the weapons from China for destruction.
When the emperor read about the reports that some giants wearing the Yi-di barbarian clothes
were spotted
to the west of Xianyang (Chang'an) the capital, he ordered the metals to be melted and made into 8 bronze [and aluminium] statutes in the image of the giants -- which were not what J. P. Mallory and Victor H. Mair speculated to be the "Caucasians" simply because they were recorded to be taller than the Mongoloid Chinese.

This webmaster never thought the people of the Central Asia or in Chinese Turkestan were an intermediary form of human evolution,
which was the basis of calling the Siberian origin of the Koreans a 'moo' point.
This webmaster had pointed out that in the collective memory of the Sino-Tibetans, that passed down by generations through millennia,
the Sinitic Chinese had forgot that they had travelled north from today's Burma-Vietnam while claiming to have walked down Mt Kunlun.
Previously, this webmaster checked into the historical context as well as the geo situation to find out about when the east met with the west,
and believed that the 3rd century B.C.E. Hun-Yuezhi War could be the start of the contact.
With the new archeological findings, this webmaster would add that the proto-Tibetan Qiangs had indeed penetrated into Chinese Turkestan,
to the north side of Mt Tianshan, from perhaps the southeastern rim of the Taklamakan Desert, 2000 years ahead of the Hun-Yuezhi War.

The Mallory and Mair claim that the ancient people taking a single northern-altitude route of west-to-east travel to Siberia, Northeastern Asia and the American continent, could be a simplistic deduction.
The Mongoloid origin was one, and it was the southern origin in today's Southeast Asia. 50-60,000 years ago, it was the D-haplogroup people, and then 30,000-50,000 years ago, it was the C-haplogroup people. They were followed by the entry of the N-O haplogroup people into the Asian continent about 15,000 years ago.
The report done by the National Geographic team headed by Spencer Wells, commercial in nature, was unscientific to trace the DNA of the AmerIndians to some person living in the Caucasus 40,000 years ago, at which time the Caucasoid and Mongoloid peoples might not parted their ways yet.
The recent DNA studies showed that there were two separate paths taken by the O-N people towards East Asia and by the Q-R people towards the Caucasus, with the later cross-mixing among the N and R people to form the ancestors of today's Indo-Europeans.
There was also a DNA study on some cattle in southern Siberia, which derived an interesting finding that those animals actually moved through the Tibetan plateau, and then the Pamirs mountain range to reach Siberia in a half-circle movement.

Click on the below picture for the enlarged map showing the first Hunnic attack at the Yuezhi possibly around the ancient Juyan Lake
(also known as the West Sea in the Chinese classics, and later known as the
Kharakoto [Blackwater] Lake, Ejina or Juyan - before this 'West Sea' concept was applied to today's Qinghai-hu Lake by the usurper-emperor Wang Mang when he set up the Xi-hai-jun commandary using the imaginary four-sea concept in SHAN HAI JING).
The reason that this webmaster made this hypothesis is that the Huns were more subsequently recorded to have fought another war against the Wushun, Loulan, Hujie and etc, i.e., the twenty-six statelets of Chinese Turkestan, at the place somewhere near Yiwu in the 2nd century B.C.,
to the east of Turpan, which then triggered the Wusun migration to Ili where they further drove the Yuezhi towards
today's Afghanistan.

The exact timeline is like this:
Hunnic chanyu Mote ascended to the throne in about 209 B.C. after killing father Touman who earlier sent Mote to the Yuezhi as a hostage and then attacked the Yuezhi to induce the Yuezhi into killing Mote.
The Huns under Mote Chanyu first defeated the Eastern Hu nomads [at possibly the Pine Desert area or the origin of the Liao-he River] in 206 B.C., then attacked the Yuezhi to the west at about 203 B.C.E. (i.e., the 7th year reign of Mote),
which triggered the Yuezhi's chain reaction against the Wusun, killing the Wusun king,
and the Huns possibly took control of the Western Corridor [i.e., the He-xi Corridor] by that time.
Mote Chanyu took custody of the Wusun prince and allocated the land in the western territories to the Wusun; however,
the new Wusun king, after growing up, distanced himself from the Huns.
The Huns attacked to the west against the Yuezhi around 176 B.C., hence defeating the tribal desert states of Loulan, Wusun and Hujie etc, in a battle near today's Yiwu per Yu Taishan, and taking control of the 26 statelets in Chinese Turkistan.
This war was relayed to the Chinese emperor in Mote's letter, stating that it was executed as punishment of the Hunnic rightside virtuous king for his distubing peace with China.
In 174 B.C., the newly-enthroned Chanyu Laoshang sent some scouts in search of the Yuezhi and mounted another campaign against the Yuezhi, killed the Yuezhi king, and made the king's skull as a drinking utensil.
The Yuezhi queen acted as a regent and led her people in a further move to the west.
The Yuezhi, in turn, attacked the Scythians in today's Ili River area, hence dwelling at the Ili River and the Chu-he River
[from the Ili and Chuhe river basins in the east to the Sir (Syrdarya) River valley].
In 172 B.C., Jia Yi, a counsellor for Emperor Wendi, in light of the fact that the Huns had become too powerful after defeating the Yuezhi, suggested to find a way to pacify the Huns by allowing the Huns to stay along the Great Wall for better management.
At the time of Junchen Chanyu, the Yuezhi, under the attack of possibly the Wusun-Hun alliance, relocated south to today's Afghanistan, where they again evicted the Scythians who in turn had overthrown the Tu-huo-luo kingdom earlier.
(Yang Fuxue had dispute about the exact time the Yuezhi migrated to the west: http://www.eurasianhistory.com/data/articles/l01/2024.html#_edn1 )

On the modern map, there was a tiny sand bridge between Chinese Turkistan and China, which was the narrow strip of desert sand to the east of Hami.
However, this corridor, today's Kumul line, could be a recent event.
There was the historical DA-ZI blackhole desert to the east, nowadays called by the generic name GOBI. (Specifically, near today's Hohhot, there was an ancient Chinese geological name called "zi kou", namely, the entry point into the Da-zi Desert.)
The ancient Mongoloid migration into the Tianshan Mountain could have come north from south, i.e., the Tibetan Plateau/Ruoqiang direction to the south --though this webmaster hesitated about the
passibility of the "Liu-sha" [quick sand] desert between Ruoqiang and Loulan (Lop Nur), which was another tiny sand bridge noticeable on the modern map.

Judging from Han Dynasty emissary Zhang Qian's change of mind on his return trip to go home along the Hami strip rather than going straight east across the Qiang-zhong [i.e., the middle Qiang nation land], we could tell that the northern strip was perhaps the most traveler-friendly.
(Could Zhang Qian had changed his mind in the hope of sneaking into the Hunnic territory to see the child he had with a Hunnic woman?)
That was Han Emperor Wudi's reign of B.C. 140-86, i.e., 140 BC and later, much later than the 3rd century BCE and 2nd century BCE Hun-Yuezhi wars.

While we don't know exactly what path Zhang Qian took to go west, noting that he was caught by the Huns and had stayed with the Huns for a dozen years, we could speculate that he must have taken the "safe" and "passible" path to the north, i.e., the path the Yuezhi exodus had taken, near the Tianshan and Altaic mountain ranges. We do know from his writings what path he took to return to China. Zhang took the path along the edge of the Kunlun Mountain, i.e., the southern edge of the Tarim basin/desert, and then along the Altun (Ah-er-Jin) Mountain, intending to then move through the "Qiang zhong", i.e., the middle Qiangic land, which was south of [contemporarily-named] Qilian.
Zhang's interest was to check out the source of the Yellow River, and he confirmed that there were two river systems in Chinese Turkistan,
i.e., the west-to-east Tarim River flowing down the Pamirs,
and the south-to-north Hotien River flowing down the "Nan shan" (southern mountain) which was what we Chinese called by the Kunlun Mountain since Han Dynasty Emperor Wudi's era - as the name Kunlun was personally pinpointed and santified by the emperor after reviewing Zhang Qian's report on the western territories.
However, Zhang Qian then changed mind, and in lieu of going east, he traveled north around the Lop Nur (Luobupuo area), passing the Loulan land for Gushi, which was between Loulan and today's Urumqi. On this northbound road, Zhang Qian was caught by the Huns again.
(In Chinese records, the same names were applied to the mountains in and outside of the Sinitic domain: the "Nan shan" [southern mountain] was commonly used for the Qilian Mountain range
which was itself originally named Mt. Kunlun, meaning magnificent and heavenly in Chinese, till the time the Huns defeated the Yuezhi [? at Lake Juyan]
and subsequently took over the western corridor from apparently the Qiangs [as the the western corridor was to become the demarcation line between the Qiang people and the Hu people
in th Han Dynasty, known as the segregation of the Qiangs from the Huns via the Han military garrisons built along the corridor, i.e., one of the two Han Chinese policies to weaken the Huns],
and renamed the mountain to Qilian, meaning heavenly in the Hunnic terminology. After Zhang Qian's trip to the west,
the "Nan shan" [southern mountain] came to denote the current Kunlun Mountain that ran straight into Tibet from the Pamirs, after Han Emperor Wudi [B.C. 140-86] personally termed the newly-imported Khotan jade as the Kunlun Jade, i.e., an archaic name.
The Chinese, in addition, named the present Tianshan [heavenly] Mountain of Chinese Turkestan as the "Bei shan" (northern mountain] in relativity, and the Altaic Mountain by Jinshan [gold mountain] --where the later Turkic word Altay meant for 'gold'.)

What Gen. Li Guangli did was another interesting matter worthy of noting. With Zhang Qian's walking the circle around Loulan and the Lop Nur (Luobupo area), it was not hard to figure out the depth and radius of the "Liu Sha (Kumtag, i.e., flowing sand)" desert. Hence, with the "piercing-vacuum" knowledge, Gen. Li Guangli FORCEFULLY took the straight path across the quick-sand desert. In the first trip, he lost majority of his troops to both the desert and the fighting against the natives living to the west of the Lop Nur (Luobupo area), i.e., the so-called Peacock River or Salty River, a parallel river to the Tarim River, which ended dead in the sand, and was known as the so-called "salt lake" or "Puchang Sea", with a wild claim, which was also carried in the Mountain and Sea Legends, that the water, including that from the Pamir-Tarim flow, disappeared into the ground at the Lop Nur (Luobupo area) and flowed below the earth's surface to re-appear as the source of the water for the Yellow River.
After Han Wudi Wudi [B.C. 140-86] defeated the Huns, first time ever, China built the forts and stationed the farming soldiers straight west towards the Salty Lake direction, which was a short-cut path undoubtedly and later went into oblivion when Han Dynasty's imperial power subsided over the Chinese Turkestan.

Now, let's talk about the human migration.
There were widespread discussions of the 'Caucasoid' mummies in Chinese Turkestan, with the 'Loulan Beaty' purportedly dated 2000 B.C., while the southern 'cousins' in the Khotan area dated 100-300 B.C.
The timeline suggested a move from north to south, not west to east.
The 2000 B.C. Caucasoid mummies found in Loulan, in the Turpan Depression/Kumtag Desert, in-between Altaic/Tianshan Mountains and the Altun Mountain (Ruoqiang), could be the Indo-European people coming from the north of the Altaic Mountain [the Mongol Altaic Mountain of today], near the Alfanesevo bronze culture.
Though, Yuezhi might not be of this group of people coming from north.
Further diggings in the Loulan area, i.e., the ancient Salty Lake and Salty River (Peacock Rover), led to a site called by Xiaohe or the Little River, next to the Salty River (Peacock Rover), where the Mongoloid Mummies were discovered.
It appears to this webmaster that there was indeed good carbon dating on the Xiaohe excavation, which stated that "The entire necropolis can be divided, based on the archeological materials, into earlier and later layers. Radiocarbon measurement (14C) dates the lowest layer of occupation to around 3980 ± 40 BP (personal communications; calibrated and measured by Wu Xiaohong, Head of the Laboratory of Accelerator Mass Spectrometry, Peking University), which is older than that of the Gumugou cemetery (dated to 3800)." The article claimed that the 'Mongoloid' mtDNA had similarity to some present South Siberian population. (For details, check http://www.biomedcentral.com/1741-7007/8/15 for the full article "Evidence that a West-East admixed population lived in the Tarim Basin as early as the early Bronze Age".)

The linking of this certain mtDNA in the Xiaohe/Loulan area to a modern Siberian population could be said to be circumvential at best since a lot of things might had happened in the past 4000 years.
That is, the linkage to the Siberian population could be actually an effect, not a source.
This area kind of had the same timing as the Mongoloid mummies that were discovered to the north and east of the Tianshan Mountain.
More than what was found about the mtDNA at Xiaohe/Loulan, there were mummies of the Khams-Tibetan type found to the further north,
in the Tianshan-Altaic mountain areas, which presented a much more convincing point that the proto-Tibetan Qiangs, from the south, had indeed crossed over the strip of the sand desert near Loulan to reach the north side of Tianshan.
Possibly, the Khams [proto-]Tibetan, after reaching the Tianshan Mountain Range, moved towards Hami (Qumul) to the east, where there were the Hami (Qumul) Mongoloid mummies excavated.
Note that today's Kham Tibetans were not far away from the historical Sanxingdui (three star) Excavations in western Sichuan, that was discovered by Gaway Hann (an American professor of the former Hua-xi [west China] University),
a Neolithic/Bronze culture dating from about 4800 to 2800 years ago, as well as a bridge providing Southwest China's tin to the Shang dynasty
and the Zhou dynasty.
(On the mtDNA side, the genes found among the northern Chinese women were of the mt-D5'6 type which derived from mt-D that had a history of 48000 years, and the genes among the southern Chinese women were of mt-R9 (subclade F) and mt-R11'B (subclade B) which derived from haplogroup R that had a history of 52-81000 years.
The mt-D genes were the dominant genes spanning from Asia to the American continents.
That is, the female genes had a much older history than the male genes in Asia, and could not be used for dating the prehistric human migration history.)

While the water coming down the mountain may not be salty, the salty lake did not
portend to be a source of the fresh water supply that could supply any civilization.
This webmaster's point was that the Loulan area was not a permanent settlement. Either the Indo-Europeans had come earlier than the Khams [proto-]Tibetans, or the Khams [proto-]Tibetans earlier than the Indo-Europeans.
It could be possible that the Loulan area had seen the human settlements rise and fall several times in the ancient times.
(The Peacock River that flows into the Lop Nur Lake
was known as the salty water river, and the lake was named the Salty Lake.
The terminologies could not be earlier than the Han dynasty's campaign against the Huns, and in another word, the same terminology as carried in SHAN HAI JING could mean that the said book could not have been written earlier than the Han dynasty wars with the Huns.)

This webmaster found Jan Romgard to have read much more about this mummy topic, and have a much better presentation. See http://www.sino-platonic.org/complete/spp185_silk_road.pdf.
After spending some time reading "SINO-PLATONIC PAPERS", you could see that the article said that "the Yanbulake site excavated in the mid
1980s, eight out of 29 examined skeletons were estimated to be of Caucasian origin while
the others were defined as Mongoloid, or to be more specific, 'similar' to the 'Khams Tibetan type'."
What he cited was the research showing that the so-called "Asian" mtDNA mummies were related to the Khams Tibetans, "a group within the ethnic Tibetan community situated in eastern Tibet" today.

In this sense,
no matter the Mongoloid mummies in Chinese Turkestan were linked to today's South Siberian people or today's Kham (Xi-kang) Tibetans, they could all be traced to the
original San-miao exile epic.
This webmaster's reasoning was that the Qiangs had a dominance in the area since China's prehistory, like 5000 years ago, at least the time of the Yellow Emperor [Huangdi], and they controlled the southern rim, southeastern rim and eastern rim of the Taklamakan Desert, and somehow around 2000 B.C., penetrated northward to reach the two sides of the Tianshan mountain range, while the so-called Caucasoid oases in their path, namely, the Loulan area, might have risen and fallen numerous times in history -- if they ever existed there prior to the penetration by the Khams [proto-]Tibetans.

Or the other way around, the Khams [proto-]Tibetans could be speculated to have penetrated to the two sides of the Tianshan mountain range earlier than the Indo-Europeans, and subsequently encountered the Indo-Europeans near the Tianshan Mountain, and ultimately the Indo-Europeans gradually dominated over the area and eliminated the trace of the Khams [proto-]Tibetans, pressing them back to the southeastern rim of the Taklamakan Desert.

According to Sima Qian, the 'San Miao' people were mostly relocated to western China to guard against the western border, i.e., LIU-SHA (drift sand), known as Kumtag today, with the borderline covering the Blackwater Lake at today's Mongolia border
(which was disputed by modern Chinese writer Chen Ping to mean the Blackwater River to the south of Qilian and near the Bailongjiang River of Sichuan --a seismically active place where Xu Xiangqian's Red Army
travelled through).
Lord Shun (? 2257 - 2208 B.C.; reign 2044-2006 with rule of 39 years and life of 100 years per Zhu Yongtang's adjustment of BAMBOO) relocated them to western China as a punishment for their aiding Dan Zhu (the son of Lord Yao) in rebellion. To the west of today's Dunhuang of Gansu Province was a mountain named 'San Wei Shan' where the Three Miao peoples were exiled. ('San Wei Shan', a three-peak mountain across the Dunhuang Grotto, literally meant for the San-miao Precarious Mountain.)
This could lead to a sound speculation that the Sino-Tibetan speaking San Miao people had dwelled in Gansu much earlier than the later Indo-European Yuezhi people --should they had ever moved east to the Juyan Lake at all to be in conflicts with the Huns in the 3rd century B.C. (The more likely case was that: the Yuezhi people were not Indo-European but a subset of the exiled barbarians in Northwest China, who were to become the five Rong groups named as Yiqu, Yuzhi, Wuzhi, Xuyan and Penglu at the time of Zhou King Muwang's northwestern campaign in the 10th century B.C.E.)
The approximate date would be after 2258 BC [or more likely after 2044 B.C.E. per BAMBOO] for the San Miao relocation.
The San-miao migration was an epic that was extensively researched by Feng Shi, Bian Ren and Chen Ping et al
[the ranks among whom could have been the most notorious forgery generation of the P.R.C. in the late 20th century].
While the route of research
in linking the excavated ancient pictagraphs [ ! possibly a forgery ! ]
on the Shandong peninsula to Southwest China's Yi-zu minority's writing was tenuous,
the extrapolations on basis of
historical namings of the Yi (misnomer Dong-yi) statelets and tribes as well as the historical namings of places in the Anhui-Henan-Hubei tri-provincial areas are sound enough
to trace the ancient tribal migration to derive several conclusions: i) that the ancient Chi-you Tribe was the Yi people who migrated towards Anhui-Henan-Hubei to
mix up with the San-miao people at the Yangtze; ii) that elements of the Yi tribes joined the San-miao's exile towards Northwest China where they developed into
the later Xian-yun barbarians (Huns) as well as co-mingled with the natives to become the ancient Jiang-rong; and iii) that a branch of the San-miao/Yi exiles
moved south to Southwest China to become the Di-qiang barbarians and today's Yi-zu minority people.
(The character 'Yi', as shown above, was originally a neutral-meaning character denoting the people living in today's eastern China and along the coast,
but later got mutated in the meaning to mean for the barbarians in the east, and
later again expanded to be more an inclusive word to mean all aliens or barbarians.
As Wang Zhonghan had researched, the ancient Huns belonged to the Jiang-rong group, not the Tungunsic group that attacked west from Manchuria.)

There could have been a striking similarity between the Mongol attack at the Tanguts in the 13th cent. A.D. and the Hun attack at the Yuezhi in the 3rd cent. B.C.
Both took the desert road towards the Blackwater Lake.
(Hunnic chanyu Mote's father had of course first attacked the Yuezhi at about 209 B.C.E. The later Mongols attacked west along the desert road while Han Dynasty general Huo Qibing took the same direction to attack the Huns.)
It kind of gives you a picture as to how chanyu Mote's Huns first raided to the west against the Yuezhi, forcing the Yuezhi Major to flee west while the elderly and the children, i.e., the Yuezhi Minor,
crossed the Qilian mountain to seek asylum with the Qiangs, and per Yu Taishan, continued to move on towards the southeastern rim of the Taklamakan Desert,
towards
Khotan where the people were recorded to be Mongoloid, i.e., the Hua-xia-looking, throughout China's Han and Tang dynastic records, till annihilated sometime during the Islamic invasion of the
Buddhist stronghold of Khotan or possibly during the earlier Turkic-Uygur conquest of the Chinese Turkistan.
(Note the discovery of the so-called 100-300 BC Caucasoid in Khotan, which matched with the escape timeframe of the Yuezhi Minor.
Another recent writing on Zhou King Muwang's travelogue at the imperialchina.org blog, available in pdf format
[Mu-tian-zi.pdf],
exhibited the westernmost extent of the ancient Chinese kingdom to be no more than the edge of the Kumtag Desert and right at the Black Water Lake.)

This webmaster tried to reconcile Sima Qian's statement in regards to the migration of the Lesser Yuezhi,
in the aftermath of the Huns' attack in the last years of the 3rd century BCE,
to give the Yuezhi people some credit of living a bit further to the east, i.e.,
staying somewhere near the Blackwater Lake [i.e., the Ejina or Juyan Lake].
By making this assumption, this webmaster assumed that the Lesser Yuezhi people, namely, the sick, the elderly and the young,
climbed the Qilian-shan Mountain [today's Qilian-shan, not what Yu Taishan et al had postulated to be the Tianshan
or the Heavenly Mountain Range in Turkestan] to live among the Qiangs
--unless Sima Qian actually meant that the Huns had raided deep into the Chinese Turkestan in the first place,
driving the Greater Yuezhi into a flee towards the Ili area to the west and the Lesser Yuezhi into a move across today's Tianshan
or the Heavenly Mountain Range to live with the Qiangs in Khotan, at the southeastern rim of the Taklamakan Desert,
a historical dwelling place of the Qiangs since the late 3rd millennium BCE.
(According to the excavated bamboo strips (slips) from the Lake Juyan area, the original Yuezhi people, after 80 years or 3-4 generations since the first Hunnic attack against them, still dwelled in large numbers at the Lake Juyan.)

In conclusion, there were two points of contact between the west and the east, one time around the 2000 BCE, and another time in the 4th century BCE (or more exactly the 3rd century BC when the Huns attacked the Yuezhi, triggering the chain reaction to the west).
The demarcation point of the 4th century BCE or the 3rd century BCE was important in determining the second point of contact between the Mongoloid and the Caucasoid,
after the first Mongoloid-Caucasoid mummy contact around 2000 BCE near today's
Tianshan or the Heavenly Mountain, known as Bei-shan or the Northern [Turkestan] Mountain at Han Emperor Wudi's timeframe.
It would be in the 4th century BCE that Shi-zi first wrote down the sentence speculating that 2000 years earlier, at the time of the
Yellow Overlord, there were the deep-eyesocket people living to the north.
This brilliant piece of work by Shi-zi apparently adopted some then-current information available as of the 4th century BCE, in a similar fashion to
the later forgery Guan-zi which, relying on the then-current information available as of the 1st century AD, claimed that
Qi Hegemony Lord Huan'gong had crossed the Kumtag Desert to conquer the Yu-shi [or misnomer Yuezhi] people.
(Shi-zi could be a latter-day add-on as well since half of the original texts were lost in the Three Kingdom time period, and the majority of the re-compiled texts were lost again in Song Dynasty. One important fact about Shi-zi that this webmaster want to emphasize is that it could be on the same par as the classics SHAN HAI JING, i.e., the Book of Mountains and Seas, and the author or the authors of some of the contents of the two books of SHI ZI and SHAN HAI JING could be of the same origin.)

Extrapolation of prehistoric people using the mitochondrial and nuclear DNA analysis, as well as cranial analysis, on the ancient remains extracted from the archaeological sites
In 2012, Li Hongjie of Jirin University published a study of the ancient DNA analysis of the Y chromosomes of prehistoric people dwelling in northeastern China, northern China, and northwestern China.

What could be extrapolated from the above data was that the Sino-Tibetan O3-haplotype people, moving along the south-to-north Yellow River east of the Taihang mountain range, had pushed northward to the western Liaoning area of today's Manchuria, about the origin of the Liao-he River, and stayed there 5000 years ago.
In the Sinitic homeland of today's southern Shanxi, there was the excavation of the Taosi Culture (2500/2400 B.C.-1800 B.C.) since 1978, with the early-stage Taosi residents genetically identified to be of the O3-M122, subhaplogroup O3-M134 type.
According to the continuing archaeological excavation and analysis, the early Taosi people, hundreds of years later, were destroyed by the mid- and late-stage people with slightly different cranial characteristics, with some pending genetical analysis to possibly infer the western move of the O2/O1 haplotype people.
The cranial analysis of the ancient dwellers as far north as the Nen-jiang River (Pingyangzhen, Tailai, Heilongjiang) shed light on the audacious northernmost penetration of the O-haplotype people to the heartland of the C-haplotype people.

Moving ahead of the O3 Sino-Tibetan people would be the N-haplotype cousin-tribe which populated the whole belt of today's Inner Mongolia front about 5500 years ago. To the east, the N-haplotype people converged with the O3-haplotype cousins in today's western Liaoning area for the next 2500 years. To the west, the N-haplogroup people reached today's northern Chinese Turkestan about 4000 years ago, replacing the C-haplogroup people and the proto-Europeans called the Andronovo type.

The C-haplogroup people, who arrived in Asia like 50,000 years ago but were marginalized towards Siberia, northeastern Manchuria and coastal islands, began to gradually push back to the south, taking over the western Liaoning area about 2500 years ago and coinciding with the historical events known as the Hun-Donghu [i.e., the Eastern Hu barbarians] Wars around the ancient Songmo [pine desert] area.

The Q-haplotype (Q1a1-M120) people, whose main group had moved across the Bering Straits to the American continent 10,000-15,000 years ago, saw some remnants migrating southward.
About 3000 years ago, the Q-haplotype people, with a weight of 41% among the remains analyzed, were seen to have penetrated south to have reached Jiangxian in today's southern Shanxi Province, as seen in the remains found in the possibly [patented Xia dynastic] Si-surnamed Peng-guo state, next to the Jinn Principality.
From the Peng-guo's intermarriage with the Ji-surnamed Rui-guo and Bi-guo states, it could be sensed that the Peng-guo people did have something which made them prestigous, possibly the bronzeware utensils.
The purportedly same 'Peng' character found on the Shang oracle bones could mean the existence of the advanced bronze culture Peng-guo state as early as the Shang dynasty time period.

The Q1a1-M120 people, found in Pengyang, also populated today's western Yellow River Bend about 2500 years ago, coinciding with the historical events known as the Hun-Yuezhi Wars.
(The Yuezhi people, who were evicted by the Huns towards the Amu Darya and Syr Darya river area, were said to have left behind a Yuezhi Minor group that relocated to the south of Mt. Qishan, where cranial analysis of the ancient remains, such as from the Mogou (grind ditch) cemetry in Lintan, Gansu, found only the continuous flow of the Sino-Tibetan population among the Siwa, Siba and Xindian culture sites.
Note that the Pengyang locality was to the further west of Qingyang which in turn was to the west of the Zhou people's south-north Binxian-Qishan habitat, with the Zhou people's southern relocation having something to do with its historical conflict with the Gui-fang/Xunyu/Rongdi people, a group of people having intermarriage with the legendary fire guardian Zhu-rong (known as Lu-zhong-shi in the DI XI section of DA-DAI LI-JI) and carrying the archaic Kui surname, who had extensive presence in the northern China's domain and a history as early as the start of the Sinitic civilization.
That is, the Zhou ancestors were separated from the Q1a1-M120 people by the Gui-gang/Xunyu/Rongdi barbarians.
The Q1a1-M120 people, however, could be closely situated to the J2-surnamed Mixu state in today's Lingtai of Gansu Province, i.e., a state that Zhou King Wenwang conquered in the early 11th century B.C. and Zhou King Gongwang eliminated in the late 10th century B.C.
This webmaster, having debunked the Aryan bearer theory for the bronze, chariot and wheat's arrival in China, sorted through the history records to find substantiation but could not come up with any evidence.
The non-Sinitic evidence would be the non-Asian-continent genetical mark of Q1a1-M120 which was found among the ancient Pengyang/Jiangxian tomb remains and still had a minor presence in today's Chinese population.)

Li Hui, in the article "Y chromosomes of prehistoric people along the Yangtze River", concluded that the analysis of the ancient Yangtze River people showed that "at least 62.5% of the samples belonging to the O haplogroup, similar to the frequency for modern East Asian populations. A high frequency of O1 was found in Liangzhu Culture sites around the mouth of the Yangtze River, linking this culture to modern Austronesian and Daic populations. A rare haplogroup, O3d, was found at the Daxi site in the middle reaches of the Yangtze River, indicating that the Daxi people might be the ancestors of modern Hmong-Mien populations, which show only small traces of O3d today."
More recent genetical studied concluded that Y Chromosomes of 40% Chinese Descend from Three Neolithic Super-Grandfathers, with the main patrilineal expansion in China having "occurred in the Neolithic Era and might be related to the development of agriculture", corresponding with the middle Neolithic cultures such as Yangshao (6.9-4.9 kya) and Dawenkou Culture (6.2-4.6 kya) in the Yellow River Basin.